Flavius Josephus, Antiquities of the Jews
William Whiston, A.M., Ed.

[260] Now while these men were thus talking one to another, Esther's eunuchs hastened Haman away to come to supper; but one of the eunuchs, named Sabuchadas, saw the gallows that was fixed in Haman's house, and inquired of one of his servants for what purpose they had prepared it. So he knew that it was for the queen's uncle, because Haman was about to petition the king that he might be punished; but at present he held his peace. Now when the king, with Haman, were at the banquet, he desired the queen to tell him what gifts she desired to obtain, and assured her that she should have whatsoever she had a mind to. She then lamented the danger her people were in; and said that "she and her nation were given up to be destroyed, and that she, on that account, made this her petition; that she would not have troubled him if he had only given order that they should be sold into bitter servitude, for such a misfortune would not have been intolerable; but she desired that they might be delivered from such destruction." And when the king inquired of her whom was the author of this misery to them, she then openly accused Haman, and convicted him, that he had been the wicked instrument of this, and had formed this plot against them. When the king was hereupon in disorder, and was gone hastily out of the banquet into the gardens, Haman began to intercede with Esther, and to beseech her to forgive him, as to what he had offended, for he perceived that he was in a very bad case. And as he had fallen upon the queen's bed, and was making supplication to her, the king came in, and being still more provoked at what he saw, "O thou wretch," said he, "thou vilest of mankind, dost thou aim to force in wife?" And when Haman was astonished at this, and not able to speak one word more, Sabuchadas the eunuch came in and accused Haman, and said," He found a gallows at his house, prepared for Mordecai; for that the servant told him so much upon his inquiry, when he was sent to him to call him to supper." He said further, that the gallows was fifty cubits high: which, when the king heard, he determined that Haman should be punished after no other manner than that which had been devised by him against Mordecai; so he gave order immediately that he should be hung upon those gallows, and be put to death after that manner. And from hence I cannot forbear to admire God, and to learn hence his wisdom and his justice, not only in punishing the wickedness of Haman, but in so disposing it, that he should undergo the very same punishment which he had contrived for another; as also because thereby he teaches others this lesson, that what mischiefs any one prepares against another, he, without knowing of it, first contrives it against himself.